tert-Butyl peroxybenzoate
[CAS# 614-45-9]

Identification

• Classification: Chemical reagent >> Organic reagent >> Ester >> Butyl ester compound
• Name: tert-Butyl peroxybenzoate
• Synonyms: tert-Butyl perbenzoate; TBPB
• Molecular Formula: C₁₁H₁₄O₃
• Molecular Weight: 194.23
• CAS Registry Number: 614-45-9
• EC Number: 210-382-2
• SMILES: CC(C)(C)OOC(=O)C1=CC=CC=C1

Properties

• Density: 1.021
• Melting point: 8 °C
• Boiling point: 75-76 °C (0.2 mmHg)
• Flash point: 200 °F
• Refractive index: 1.498-1.500
• Water solubility: Immiscible

Safety Data

• Hazard Symbols: GHS02;GHS07;GHS09 Danger
• Risk Statements: H242-H315-H317-H332-H400-H412
• Safety Statements: P210-P234-P235-P240-P261-P264-P271-P272-P273-P280-P302+P352-P304+P340-P317-P321-P332+P317-P333+P317-P362+P364-P370+P378-P391-P403-P410-P411-P420-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Organic peroxides	Org. Perox.	C	H242
Skin sensitization	Skin Sens.	1	H317
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Acute toxicity	Acute Tox.	4	H332
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Organic peroxides	Org. Perox.	F	H242
Oxidising liquids	Ox. Liq.	3	H272
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Eye irritation	Eye Irrit.	2	H319
Organic peroxides	Org. Perox.	B	H241
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Flammable liquids	Flam. Liq.	1	H224
Organic peroxides	Org. Perox.	D	H242
Oxidising liquids	Ox. Liq.	2	H272
Self-reactive substances or mixtures	Self-react.	C	H242

• Transport Information: UN 3103

Discovery and Applications

Tert-butyl peroxybenzoate (TBPB) is an organic peroxide widely used in polymer chemistry as a free radical initiator in a variety of chemical processes. Its ability to decompose and release free radicals makes it valuable in polymer production and other chemical reactions.

TBPB was first synthesized in the mid-20th century as part of a wider exploration of organic peroxides for industrial applications. Organic peroxides have attracted attention for their potential to decompose and generate free radicals under mild conditions. TBPB, in particular, has been developed for its effectiveness in initiating polymerization reactions. Its ability to generate free radicals at moderate temperatures and its liquid state at room temperature have made it a versatile choice for a variety of industrial processes.

The primary application of TBPB is as a free radical initiator, but it can also be used in other areas. TBPB is widely used in the polymer industry as an initiator for the polymerization of monomers such as styrene, acrylates, and methacrylates. Its ability to effectively generate free radicals helps control the polymerization process, resulting in high-quality polymers with desired properties. TBPB is particularly useful in the production of polystyrene and various resins.

In the rubber and plastics industry, TBPB is used as a crosslinking agent. It helps form cross-linked structures in rubber, which enhances its mechanical properties, heat resistance, and elasticity. This application is essential for making durable rubber products such as tires and industrial belts.

TBPB is used in the curing of unsaturated polyester resins. By initiating the polymerization of the resin with monomers such as styrene, TBPB helps form hard thermoset plastics. This process is essential for producing fiberglass reinforced plastics used in automotive, marine, and construction applications.

As an organic peroxide, TBPB needs to be handled with care as it can decompose explosively under certain conditions. It should be stored away from heat sources with appropriate safety precautions, including protective clothing and adequate ventilation.

References

2022. Radical C(sp3)-H Functionalization and Cross-Coupling Reactions. *Nature Reviews Chemistry*, 6. DOI: 10.1038/s41570-022-00388-4

2022. Copper-Catalyzed Alkylation of Quinoxalin-2(1H)-ones with Styrenes and tert-Butyl Peroxybenzoate. *Synlett*, 33(10). DOI: 10.1055/a-1815-3539

2022. TBPEH-TBPB Initiate the Radical Addition of Benzaldehyde and Allyl Esters. *International Journal of Molecular Sciences*, 23(22). DOI: 10.3390/ijms232213704